1. Field of the Invention
The present invention concerns an aspect of the design and operation of cotton gins. More specifically, the present invention is directed toward a system and related method for recirculating air in a cotton gin.
2. Description of the Prior Art
Since the cotton gin was first developed by Eli Whitney more than a century ago, the basic task of separating seeds, plant material, and other objects from the fibers of the cotton has remained a primary concern among cotton ginners. These various objects or xe2x80x9ctrashxe2x80x9d are typically collected together with the raw cotton when it is harvested, and must be separated from the cotton fibers before the cotton can be processed into thread and, ultimately, into fabric.
Although many configurations of processing machinery are possible, and generally well known, typically, upon arrival to a cotton gin, the raw or harvested cotton is first received by a dryer system, such as a tower dryer, followed by either an extractor or cleaner. The tower dryer subjects the cotton to previously generated heat to adjust the moisture content of the cotton in order to facilitate the ginning of the cotton. This heat is generated by a conventional burner and fan assembly, in which the cotton is directly exposed to and conveyed by this heated stream of air. After exiting the dryer system, the cotton travels to either an extractor or cleaner. The extractor removes larger objects, such as burrs or sticks, while the cleaner removes smaller objects, such as seeds or plant material.
To initially convey the cotton from the dryer to the extractor or cleaner, the burner and fan assembly, located in line before the inlet of the dryer, directs a heated air stream toward the inlet, thus, projecting the cotton and other objects toward the inlet. This same burner and fan assembly, or another similar assembly, provides the heated air stream to the tower dryer that facilitates the drying of the cotton. Once exiting the extractor or cleaner, the cotton continues through the cotton gin for further ginning, as conveyed by an air stream generated by another burner and fan assembly. After completing this process, the cotton remains in the gin, while the independent air streams, now including trash and other particles separated from the cotton, exhausts into the atmosphere. Each individual air stream, originating from the different burner and fan assemblies, must exhaust into the atmosphere because each burner requires new air. Indeed, the provision of used air or air containing small trash or lint to a burner and fan assembly presents the danger of fire, as the small trash or lint may ignite due to the high temperatures in the burner. For this reason, after an air stream comes in contact with the cotton and other debris residing in the cotton, it is expelled from the cotton gin, as its conveyance to another burner and fan assembly would introduce the risk of fire to the ginning process.
Cotton gins have also employed air flow systems using multiple burner and fan assemblies positioned at both the entrance and the exit of the gin. For example, in the initial conveyance of the cotton, the gin may employ a burner and fan assembly located in line before the inlet of the tower dryer that creates a heated air stream pushing the cotton forward. As positioned, the assembly directs a heated air stream toward the tower dryer and continuing to the extractor or cleaner to project the cotton and other objects into the extractor or cleaner. Again, this same burner and fan assembly, or another similar assembly, also provides heated air to the tower dryer in order to dry the cotton. Additionally, another burner and fan assembly, employing a pull fan, may be positioned in line after the outlet of the extractor or cleaner to pull the cotton along for further processing.
But inherent in each of these systems is the continued exhaust of air streams of trash and other particles into the atmosphere. In this increasingly environmentally-conscious marketplace, the unhampered exhaust of air including particles of trash violates regulations on pollution. The inability of conventional cotton gins to incorporate features that continue to maximize the operation and efficiency of cotton ginning, while reducing the amount of pollution expelled into the environment has created a specific need for alternative techniques for directing air flow through the cotton gin.
The present invention addresses these concerns by providing an air flow system that maximizes efficiency while reducing pollutant emissions.
The advantages and purpose of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages and purpose of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
To attain the advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the closed loop push/pull system of the present invention employs a hot shelf tower dryer and a plurality of fans uniquely positioned throughout portions of the cotton gin to direct and recirculate air through the cotton gin. Because the system employs a hot shelf tower dryer, the conventional introduction and circulation of hot air from a burner and fan assembly, after the primary burner, is no longer necessary. Instead, the hot shelf tower dryer may adjust the moisture content of the cotton through its heated shelves, the shelves being internally heated by hot air provided by a burner and fan assembly. The provision of the hot shelf tower dryer reduces the need for new air and limits the expulsion of air into the atmosphere caused by conventional drying methods, because much of the heated air is recirculated within the system.
To convey the cotton, the closed loop push/pull system provides a first fan, positioned before the hot shelf tower dryer, that provides an air stream conveying the cotton toward the dryer, so that the dryer, through its heated shelves, may adjust the moisture content of the cotton. The air stream continues to convey the cotton from the dryer to a cleaner or extractor of the cotton gin, so that trash may be separated from the cotton. Once separated, the air stream continues to convey the separated trash to a collector to separate the trash from the air stream conveying it. At minimum, the system further includes a second fan, positioned after the collector, that generates an air stream that withdraws the separated air from the collector and conveys it to a filtering system to clean the air. The cleaned air may then be pulled from the filtering system to the first fan, so that it may be recirculated through the system. Alternatively, the cleaned air may be directed before either the cleaner or the extractor for recirculation. By limiting conventional drying methods (i.e., exposing the cotton directly to a heated air stream) and by recirculating much of the air, by using fans that generate air streams that push as well as pull air, the system maintains the efficiency of the cotton gin, while reducing the emission of pollutants into the atmosphere. The number of fans employed by the system depends upon the number of dryers, cleaners/extractors, and collectors used in the cotton gin.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.